1. lacking or showing a lack of what is fitting and considerate in dealing with others

- in the circumstances it was tactless to ask her age

Similar word(s): inconsiderate, inelegant, untactful

2. revealing lack of perceptiveness or judgment or finesse

- it was tactless to bring up those disagreeable

Similar word(s): maladroit, inept

Sentences with tactless as an adjective:

- It was tactless of you not to attend your sister's wedding.